cerf’s upA Brittle and Fragile FutureWhile this is not intended to be a dystopianrant, I feel strongly motivated to drawattention to the fragile and interdependentfuture we are creating through the use of

programmable devices and systems.
Some of you are, no doubt, rather
tired of this theme, but as we equip cyber-physical and virtual systems with
programs that animate their functions, it seems inescapable that over
time they will become increasingly interdependent and that may produce
vulnerabilities and fragilities that will
be exploited by inimical parties or will
simply create difficult and even unrecoverable failures.

Consider systems that use passwords and two-factor authentication
to identify users. It is often advised to
have alternative means for authentication: a mobile device, a distinct email
account, a phone number, or an alternative means of identification. These
kinds of interdependencies can lead
to cascade failures where loss of access to one system initiates failures in
others until a complex of authentication failures render a user unable to
use any of them. Loss or cancellation
of an email account or a mobile phone
number may have later consequences
if users do not remember to revise all
accounts dependent on these alternative means of identification. They may
discover the oversight just when the
alternatives are vitally needed.

Multiple platforms that support
common services such as Alexa or
Google Assistant may be concurrently
invoked, leading to confusion as to
which is “in charge” at the moment.
The situation is exacerbated when
multiple users are interacting with the
same set of platforms or when the platforms are distant from one another.

Conflicting commands from authorized but uncoordinated parties could
easily lead to instability or even damage physical and virtual systems.

An analogy might be apt. Personal
computers were designed initially to
be exactly that: isolated computers for
personal use. But before long, they became valuable avenues to access and
use of the Internet. Not much thought
had been put into the security of these
systems when they were stand-alone
devices and viruses and worms were
already propagating by Sneakernet via
floppy-disk drives. The Internet and its
predecessors including bulletin board
systems were new vectors through
which malware could travel and various
attacks could be executed. A great deal
of effort had to be expended to improve
the resistance of personal computers to
various forms of attack and failure.

Many of the devices that are considered cyber-physical systems may
suffer from a similar oversight. Often
the designers see them as a single-user device controlled from an application running, for example, in the
user’s mobile smartphone. What is
emerging, however, is a highly connected ecosystem of devices and
networks with emergent properties
derived from the rich, diverse, and
distributed connectivity they exhibit.
Concerns for safety, security, privacy,
and control must be assuaged by systematic analysis of increasingly complex use scenarios. It might even be
argued that these analyses will need
to be carried out automatically just to
keep up with the non-linear growth in
potential use cases and device interactions as the devices proliferate.

The designers of devices that populate the Internet of Things have an ethical responsibility to be attentive to the
hazards their interactions may create
and the companies that market the devices and their services may ultimately
be charged by society with liability for
their failures or the abuses they invite.
It is not too early to begin thinking
about these kinds of problems and how
they might be addressed technically,
legally, and ethically by the engineers
and scientists whose advances make
new capabilities possible, but which
may have unknown consequences as
their use proliferates.

Vinton G. Cerf is vice president and Chief Internet Evangelist
at Google. He served as ACM president from 2012–2014.